Unable to hear anything on OUT

I have a simple setup. I want to take the input off the IN 1/4" jack and play it back on the OUT 1/4" jack. To do this I am using SoX and a simple script.

/usr/bin/sox --single-threaded --no-dither --buffer 131072 -t alsa --rate 192000 --channels 2 ${IN} -t alsa --rate 192000 --channels 2 ${OUT}

This gives me a simple input vu meter that shows there is signal arriving on the IN and it is getting processed (I can record it and play it back on a different system). But I am unable to hear anything on the OUT port.

I have tried the following output devices:

  1. a 1/4" -> USB connector attached to another system
  2. plugging in an amplifier.
  3. a 1/4" -> 1/8" adapter and headphones I use every day.

I happen to have 2 pisound devices. Neither of them work for output. Any suggestions?


I burned a new OS image and now it seems to work.

Did the software produce any error? The output could have been blocked by some other program running at the same time.